Re: [PATCH v3 6/9] hw/mem/cxl_type3: Add DC extent list representative and get DC extent list mailbox support

[Jonathan Cameron via <qemu-devel@nongnu.org>]

On Tue,  7 Nov 2023 10:07:10 -0800
nifan.cxl@gmail.com wrote:

> From: Fan Ni <fan.ni@samsung.com>
> 
> Add dynamic capacity extent list representative to the definition of
> CXLType3Dev and add get DC extent list mailbox command per
> CXL.spec.3.0:.8.2.9.8.9.2.
> 
> Signed-off-by: Fan Ni <fan.ni@samsung.com>
A few minor comments inline.

J
> ---
>  hw/cxl/cxl-mailbox-utils.c  | 73 +++++++++++++++++++++++++++++++++++++
>  hw/mem/cxl_type3.c          |  1 +
>  include/hw/cxl/cxl_device.h | 23 ++++++++++++
>  3 files changed, 97 insertions(+)
> 
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index 1f512b3e6b..56f4aa237a 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -82,6 +82,7 @@ enum {
>          #define CLEAR_POISON           0x2
>      DCD_CONFIG  = 0x48,
>          #define GET_DC_CONFIG          0x0
> +        #define GET_DYN_CAP_EXT_LIST   0x1
>      PHYSICAL_SWITCH = 0x51,
>          #define IDENTIFY_SWITCH_DEVICE      0x0
>          #define GET_PHYSICAL_PORT_STATE     0x1
> @@ -1286,6 +1287,75 @@ static CXLRetCode cmd_dcd_get_dyn_cap_config(const struct cxl_cmd *cmd,
>      return CXL_MBOX_SUCCESS;
>  }
>  
> +/*
> + * CXL r3.0 section 8.2.9.8.9.2:
> + * Get Dynamic Capacity Extent List (Opcode 4810h)

4801h

> + */
> +static CXLRetCode cmd_dcd_get_dyn_cap_ext_list(const struct cxl_cmd *cmd,
> +                                               uint8_t *payload_in,
> +                                               size_t len_in,
> +                                               uint8_t *payload_out,
> +                                               size_t *len_out,
> +                                               CXLCCI *cci)
> +{
> +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> +    struct get_dyn_cap_ext_list_in_pl {
> +        uint32_t extent_cnt;
> +        uint32_t start_extent_id;
> +    } QEMU_PACKED;
> +
> +    struct get_dyn_cap_ext_list_out_pl {
> +        uint32_t count;
> +        uint32_t total_extents;
> +        uint32_t generation_num;
> +        uint8_t rsvd[4];
> +        CXLDCExtentRaw records[];
> +    } QEMU_PACKED;
> +
> +    struct get_dyn_cap_ext_list_in_pl *in = (void *)payload_in;
> +    struct get_dyn_cap_ext_list_out_pl *out = (void *)payload_out;
> +    uint16_t record_count = 0, i = 0, record_done = 0;
> +    CXLDCDExtentList *extent_list = &ct3d->dc.extents;
> +    CXLDCDExtent *ent;
> +    uint16_t out_pl_len;
> +    uint32_t start_extent_id = in->start_extent_id;
> +
> +    if (start_extent_id > ct3d->dc.total_extent_count) {
> +        return CXL_MBOX_INVALID_INPUT;
> +    }
> +
> +    record_count = MIN(in->extent_cnt,
> +                       ct3d->dc.total_extent_count - start_extent_id);
> +
> +    out_pl_len = sizeof(*out) + record_count * sizeof(out->records[0]);
> +    /* May need more processing here in the future */

Not sure what this comment is referring to... I'd be tempted to just
remove it.

> +    assert(out_pl_len <= CXL_MAILBOX_MAX_PAYLOAD_SIZE);
> +
> +    memset(out, 0, out_pl_len);

As before. It should be already zeroed.

> +    stl_le_p(&out->count, record_count);
> +    stl_le_p(&out->total_extents, ct3d->dc.total_extent_count);
> +    stl_le_p(&out->generation_num, ct3d->dc.ext_list_gen_seq);
> +
> +    if (record_count > 0) {
> +        QTAILQ_FOREACH(ent, extent_list, node) {
> +            if (i++ < start_extent_id) {
> +                continue;
> +            }
> +            stq_le_p(&out->records[record_done].start_dpa, ent->start_dpa);
> +            stq_le_p(&out->records[record_done].len, ent->len);
> +            memcpy(&out->records[record_done].tag, ent->tag, 0x10);
> +            stw_le_p(&out->records[record_done].shared_seq, ent->shared_seq);
> +            record_done++;
> +            if (record_done == record_count) {
> +                break;
> +            }
> +        }
> +    }
> +
> +    *len_out = out_pl_len;
> +    return CXL_MBOX_SUCCESS;
> +}
> +



> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index 3dc6928bc5..5738c6f434 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -420,6 +420,25 @@ typedef QLIST_HEAD(, CXLPoison) CXLPoisonList;
>  
>  #define DCD_MAX_REGION_NUM 8
>  
> +typedef struct CXLDCDExtentRaw {
> +    uint64_t start_dpa;
> +    uint64_t len;
> +    uint8_t tag[0x10];
> +    uint16_t shared_seq;
> +    uint8_t rsvd[0x6];
> +} QEMU_PACKED CXLDCExtentRaw;
Naming mismatch.

> +
> +typedef struct CXLDCDExtent {
> +    uint64_t start_dpa;
> +    uint64_t len;
> +    uint8_t tag[0x10];
> +    uint16_t shared_seq;
> +    uint8_t rsvd[0x6];
> +
> +    QTAILQ_ENTRY(CXLDCDExtent) node;
> +} CXLDCDExtent;

DCD or DC?  I don't really care but inconsistent currently.

> +typedef QTAILQ_HEAD(, CXLDCDExtent) CXLDCDExtentList;
> +
>  typedef struct CXLDCDRegion {
>      uint64_t base;
>      uint64_t decode_len; /* aligned to 256*MiB */
> @@ -470,6 +489,10 @@ struct CXLType3Dev {
>          HostMemoryBackend *host_dc;
>          AddressSpace host_dc_as;
>          uint64_t total_capacity; /* 256M aligned */
> +        CXLDCDExtentList extents;
> +
> +        uint32_t total_extent_count;
> +        uint32_t ext_list_gen_seq;
>  
>          uint8_t num_regions; /* 0-8 regions */
>          CXLDCDRegion regions[DCD_MAX_REGION_NUM];